Machinist s instrument foe determining geometrical lines



R. LIGHT.

Machinists Square.

' Patented (April '9. 1861.

2 Sheets-Sheet1,

I '2 Sheets-Shed 2. R. B. LIGHT. Machinists, Square.

Patented April 9. I861.

FFICE.

RICHARD B. LIGHT, OF DUNKIRK, NE\V YORK.

MACHINISTS INSTRUMENT FOR DETERMINING GEOll/IETRICAL LINES, CENTERS, &c.

Specification of Letters Patent No. 31,987, dated April 9, 1861.

To all whom it may concern:

Be it known that I, RICHARD B. LIGHT, of Dunkirk, in the county of Chautauqua and State of New York, have invented a certain new and useful Instrument for Mechanical Purposes; and I do hereby declare that the following is a full and exact description thereof, reference being had to the annexed drawings, and to the letters of reference marked thereon, the same making a part of this specification.

In the different figures the same letters of reference denote like parts.

The nature of my invention consists in providing an instrument of small dimensions which can be successfully used in a series of mechanical operations with perfect accuracy, and a great saving of time.

In the said drawings, Figure 1, is a perspective view of the top of the instrument. Fig. 2, is a back view of the same.

Fig. 3, is a longitudinal section.

Fig. 4, is a plan view with the box square attached.

Fig. 5, is a rear elevation of the frame H.

Fig. 6, represents the application of this instrument to the inside of a circle finding the center, when said circle is too large in diameter for outside application; also the application of the box-square (a) to project lines on the outside of a shaft, or circular body, and by which application the lines are projected with perfect accuracy.

Fig. 7, represents the application of the instrument to the out side of the circle for the purpose of finding its center.

Fig. 8, represents theinstrument attached to the box-square (a) and used as a gage by which means lines can be projected on main connecting rods, blocks, or any other work with a fiat side to it, either centering or the marking of key-ways or cutter ways.

Fig. 9, represents the application of the instrument to the cross head of a marine engine, where the level (6) and the center marker (0) are brought into use. The work being leveled, and the instrument placed over it, the level, indicates when the tool is over the center of the work to be lined, or.

marked. As soon as the level stands perfectly true, a stroke given on the top of the center marker (0) gives the exact center of the work; move it farther back, repeat the operation, and it gives the centers at both ends of the work; then apply the 'boxsquare, project the lines, and the work is laid out ready for the workman.

Fig. 10, represents the instrument fixed into the box-square for use on a surface plate, and projecting a center line through the center of a crank-shaft, or any other shaft with arms on it. The shaft is laid on blocks upon the surface plateas shown in the drawingand the instrument moved along the plate by the hand of the operator until the center line is marked as shown along its entire length.

Fig. 11, shows the manner of using the instrument, or what is sometimes called quarter-ing the crank shaft, for the purpose of placing the eccentrics. The crank is plumbed as shown in the drawing, by placing the instrument against the crank-pin,

and a piece of wood (d) the radius of which is equal to the radius of the crank-pin. The level in the instrument indicates when the crank is standing in avertical position. The crank being perpendicular, the instrument is then placed over it as shown in Fig. 9, and when the level indicates the instrument to be horizontal, strike the center marker (0,) and it will give the center. The level moving on a center, can then be turned, with its face toward the vertical crank as shown in the drawing, the instrument then turned down and placed with the center marker (0) opposite ((Z,) and struck gives the center on that side of the shaft, thus the crank is quartered with perfect accuracy, in a very short space of time. Into these centers, place a compass or divider, and mark still beyond the center the distance of the lead, and the lap of the slide over the steam post, and the exact position of the eccentric is obtained as shown at (15,) Fig. 12.

Fig. 13, shows the use of the instrument on the planing machine. l/Vhen bevel work connection With a straight edge (Gr,) When What I claim as new and desire to secure by the work is too large for the simple appli- Letters Patent is:

cation of the instrument. The combination of devices arranged sub- Fig. 16, represents the instrument on the i stantially as described, so as toconstitute 5 planing-machine marking the centers of the one instrument, whereby the several operacross head all around for' the purpose of tions herein referred to, and illustrated, may

planing. be executed as set forth.

There are but few purposes in the entire RICHARD B. LIGHT. region of mechanical operations in which In presence of 10 this instrument can not be successfully used. THOMAS FLESHER,

Having thus fully described my invention HANsoN A. RISLEY. 

